How to Bypass IP-Based Daily Limits

Some websites limit an IP address's daily quota for downloading or watching. You may use a mobile network instead of home WiFi to work around this, because a mobile network usually provides a different public IP address. You can also use a VPN, but VPN IP addresses are commonly shared by many users, so they may already be blocked, flagged, or have reached the same limit. A VPN may also be slower because traffic has to pass through the VPN server.

But if you need another rate-limit path, a machine may be able to use both a public IPv4 address and a public IPv6 address, and the browser/operating system may choose between them underneath. Assuming you currently have IPv6, you may try to force Firefox to use IPv4 as the public IP by disabling IPv6 in:
 
about:config → network.dns.disableIPv6 → click false to change it to true.

*Change it back afterward, since it may affect normal website usage. If the result does not change immediately, restart the browser to clear old DNS or connection state.

Firefox is not telling the router to “force IPv4.” If Firefox uses the target website’s A record, it has selected an IPv4 destination. The ISP may still use tunneling or translation internally, but the website receives the connection as IPv4. IPv6 cannot directly terminate on an IPv4 address unless a translation mechanism is involved.

Normal Firefox:

ask DNS for A + AAAA of target website
IPv6 exists
choose IPv6
connect from 2001:db8:1234:5678::abcd -> rate limit hit

Firefox with network.dns.disableIPv6 = true:

do not use IPv6 result
use IPv4 A record of target website
connect from 203.0.113.38 -> fresh rate limit

A and AAAA commands to check the target website and what IP the target website sees from your machine:

echo "== DNS records of target =="
dig +short A example.com
dig +short AAAA example.com

echo "== Kernel route/source choice =="
ip -4 route get 203.0.113.10
ip -6 route get 2001:db8::10

echo "== Public IP seen by external service =="
curl -4 https://example.com
curl -6 https://example.com

Output:

== DNS records of target ==
203.0.113.10
2001:db8::10

== Kernel route/source choice ==
203.0.113.10 via 192.168.0.1 dev wlo1 src 192.168.0.15
2001:db8::10 via fe80::1 dev wlo1 src 2001:db8:1234:5678::abcd

== Public IP seen by external service ==
203.0.113.38
2001:db8:1234:5678::abcd

However, Firefox does not provide a matching network.dns.disableIPv4 setting for forcing IPv6-only browsing. The options are less direct:

1. Test with an IPv6-capable website and confirm the result with an IP-checking page.
2. Make sure network.dns.disableIPv6 is set to false.
3. Turn off Firefox DNS over HTTPS if it causes Firefox to behave differently from the system resolver.
4. Prefer IPv6 at the system level through /etc/gai.conf, although this affects more than Firefox and is not a Firefox-only switch.
5. For strict IPv6-only testing, use a separate network namespace, VM, VPN, or firewall rule to make IPv4 unavailable, then launch Firefox inside that environment.

Some websites may rate-limit by account session, cookie, or browser fingerprint, so changing from IPv6 to IPv4 may also need to be combined with a different account.